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91.
Genome‐wide identification,expression profiling,and target gene analysis of microRNAs in the Onion thrips,Thrips tabaci Lindeman (Thysanoptera: Thripidae), vectors of tospoviruses (Bunyaviridae) 下载免费PDF全文
92.
Background
Domains containing the β-grasp fold are utilized in a great diversity of physiological functions but their role, if any, in soluble or small molecule ligand recognition is poorly studied.Results
Using sensitive sequence and structure similarity searches we identify a novel superfamily containing the β-grasp fold. They are found in a diverse set of proteins that include the animal vitamin B12 uptake proteins transcobalamin and intrinsic factor, the bacterial polysaccharide export proteins, the competence DNA receptor ComEA, the cob(I)alamin generating enzyme PduS and the Nqo1 subunit of the respiratory electron transport chain. We present evidence that members of this superfamily are likely to bind a range of soluble ligands, including B12. There are two major clades within this superfamily, namely the transcobalamin-like clade and the Nqo1-like clade. The former clade is typified by an insert of a β-hairpin after the helix of the β-grasp fold, whereas the latter clade is characterized by an insert between strands 4 and 5 of the core fold.Conclusion
Members of both clades within this superfamily are predicted to interact with ligands in a similar spatial location, with their specific inserts playing a role in the process. Both clades are widely represented in bacteria suggesting that this superfamily was derived early in bacterial evolution. The animal lineage appears to have acquired the transcobalamin-like proteins from low GC Gram-positive bacteria, and this might be correlated with the emergence of the ability to utilize B12 produced by gut bacteria.Reviewers
This article was reviewed by Andrei Osterman, Igor Zhulin, and Arcady Mushegian. 相似文献93.
Background
A widely-used approach for discovering functional and physical interactions among proteins involves phylogenetic profile comparisons (PPCs). Here, proteins with similar profiles are inferred to be functionally related under the assumption that proteins involved in the same metabolic pathway or cellular system are likely to have been co-inherited during evolution. 相似文献94.
AA Zahir AA Rahuman S Pakrashi D Ghosh A Bagavan C Kamaraj G Elango M Chatterjee 《Experimental parasitology》2012,132(2):180-184
Infections due to protozoa of the genus Leishmania are a major worldwide health problem, with high endemicity in developing countries. The aim of this study was to evaluate the in vitro antileishmanial activity of the acetone and methanol leaf extracts of Anisomeles malabarica, flower of Gloriosa superba, leaf of Ocimum basilicum, leaf and seed of Ricinus communis against promastigotes form of Leishmania donovani. Antiparasitic evaluations of different plant crude extracts were performed on 96 well plates at 37°C for 24-48h. Out of the 10 experimental plant extracts tested, the leaf methanol extracts of A. malabarica, and R. communis showed good antileishmanial activity (IC(50)=126±19.70 and 184±39.33μg/mL), respectively against promastigotes. Effective antileishmanial activity was observed making these plants as good candidates for isolation of antiprotozoal compounds which could serve as new lead structures for drug development. 相似文献
95.
Inamdar SR Savanur MA Eligar SM Chachadi VB Nagre NN Chen C Barclays M Ingle A Mahajan P Borges A Shastry P Kalraiya RD Swamy BM Rhodes JM Yu LG 《Glycobiology》2012,22(9):1227-1235
Glycan array analysis of Sclerotium rolfsii lectin (SRL) revealed its exquisite binding specificity to the oncofetal Thomsen-Friedenreich (Galβ1-3GalNAcα-O-Ser/Thr, T or TF) antigen and its derivatives. This study shows that SRL strongly inhibits the growth of human colon cancer HT29 and DLD-1 cells by binding to cell surface glycans and induction of apoptosis through both the caspase-8 and -9 mediated signaling. SRL showed no or very weak binding to normal human colon tissues but strong binding to cancerous and metastatic tissues. Intratumor injection of SRL at subtoxic concentrations in NOD-SCID mice bearing HT29 xenografts resulted in total tumor regression in 9 days and no subsequent tumor recurrence. As the increased expression of TF-associated glycans is commonly seen in human cancers, SRL has the potential to be developed as a therapeutic agent for cancer. 相似文献
96.
Anil Kumar P Aravind R Francis K Bhumika V Ritika C Priyashanth P Srinivas TN 《Systematic and applied microbiology》2012,35(5):320-325
Novel orange pigmented, Gram-negative-staining, rod-shaped, non-motile, strictly aerobic strains designated NIO-S1(T) and NIO-S2 were isolated from the water sample of a pond adjacent to the coast and an algal mat from a fish pond, respectively, at Kakinada, India. Both strains were positive for oxidase, catalase and β-galactosidase activities. The predominant fatty acids in NIO-S1(T) were iso-C(15:0) (39.6%), anteiso-C(15:0) (9.9%), iso-C(17:0) 3OH (10.9%) and C(16:1)ω7c/C(16:1)ω6c (summed feature 3) (5.7%). The strains contained MK-7 as the major respiratory quinine, and diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and three unidentified lipids as the polar lipids. Phylogenetic analysis indicated that strain NIO-S1(T) was a member of the family "Cyclobacteriaceae" of the class "Sphingobacteriia" and it clustered with the genera Fontibacter, Cecembia and Aquiflexum with phylogenetic distances of 6.8, 9.0 and 12.2% (93.2, 91.0 and 87.8% similarity), respectively. DNA-DNA hybridization between strains NIO-S1(T) and NIO-S2 showed a relatedness of 93% and rep-PCR banding patterns were similar. Based on data from the current polyphasic study, it is proposed that the new isolates be placed in a new genus and species with the name Shivajiella indica gen. nov., sp. nov. The type strain of Shivajiella indica is NIO-S1(T) (= KCTC 19812(T)=MTCC 11065(T)). 相似文献
97.
98.
Prabhakar V Capila I Raman R Srinivasan A Bosques CJ Pojasek K Wrick MA Sasisekharan R 《Biochemistry》2006,45(37):11130-11139
The chondroitinases are bacterial lyases that specifically cleave chondroitin sulfate and/or dermatan sulfate glycosaminoglycans. One of these enzymes, chondroitinase ABC I from Proteus vulgaris, has the broadest substrate specificity and has been widely used to depolymerize these glycosaminoglycans. Biochemical and structural studies to investigate the active site of chondroitinase ABC I have provided important insights into the catalytic amino acids. In this study, we demonstrate that calcium, a divalent ion, preferentially increases the activity of chondroitinase ABC I toward dermatan versus chondroitin substrates in a concentration-dependent manner. Through biochemical and biophysical investigations, we have established that chondroitinase ABC I binds calcium. Experiments using terbium, a fluorescent calcium analogue, confirm the specificity of this interaction. On the basis of theoretical structural models of the enzyme-substrate complexes, specific amino acids that could potentially play a role in calcium coordination were identified. These amino acids were investigated through site-directed mutagenesis studies and kinetic assays to identify possible mechanisms for calcium-mediated processing of the dermatan substrate in the active site of the enzyme. 相似文献
99.
100.
The Anabaena sensory rhodopsin transducer (ASRT) is a small protein that has been claimed to function as a signaling molecule downstream
of the cyanobacterial sensory rhodopsin. However, orthologs of ASRT have been detected in several bacteria that lack rhodopsin,
raising questions about the generality of this function. Using sequence profile searches we show that ASRT defines a novel
superfamily of β-sandwich fold domains. Through contextual inference based on domain architectures and predicted operons and
structural analysis we present strong evidence that these domains bind small molecules, most probably sugars. We propose that
the intracellular versions like ASRT probably participate as sensors that regulate a diverse range of sugar metabolism operons
or even the light sensory behavior in Anabaena by binding sugars or related metabolites. We also show that one of the extracellular versions define a predicted sugar-binding
structure in a novel cell-surface lipoprotein found across actinobacteria, including several pathogens such as Tropheryma, Actinomyces and Thermobifida. The analysis of this superfamily also provides new data to investigate the evolution of carbohydrate binding modes in β-sandwich
domains with very different topologies. 相似文献